Avian Influenzas Spreading Through European and American Farms

As we stay home, wondering how long COVID-19 will last, another disease continues to disrupt factory farms in Europe and has reemerged in U.S. farms for the first time since 2017. The disease is highly pathogenic avian influenza (HPAI), a class of viruses with multiple strains, some of which are zoonotic, or capable of infecting humans.

One HPAI strain, H5N8, has been moving through chicken and turkey farms in Europe, while in the United States, at a turkey farm in South Carolina, the strain H7N3 has reemerged—the first HPAI seen in a U.S. poultry flock since 2017. Low pathogenic avian influenza viruses, which cause less severe disease in birds, have infected U.S. poultry flocks for years. Scientists believe one of these milder strains recently mutated into a highly pathogenic one, something that could happen any time an outbreak at a farm occurs.

Influenza viruses have jumped from animals to humans several times, and because they are new to humans when they do, these viruses can potentially reach pandemic levels quickly. In recent history, humans have been infected by several zoonotic flu viruses, including H7N9, H5N1, H5N6, and H7N2 from birds and H1N2 and H3N2 from pigs.

H7N3, the strain recently detected in U.S. poultry farms, has in the past infected humans five times. While these infections weren’t fatal, other zoonotic influenza strains have resulted in loss of human life. There have been over 700 human infections with avian influenza H5N1 since 1997, and about 60 percent of people with confirmed infections have died.

Avian influenza H7N9 was first detected in humans in 2013 and has since infected at least 1,568 people, causing 616 confirmed deaths. The H1N1, or “swine flu,” pandemic of 2009–2010 killed over 18,000 people. It was caused by a virus that originated in pigs, as several viruses reassorted, or mixed, to form a new one.

While we’ve already suffered the consequences of the swine flu pandemic and lost human and animal lives to avian influenza, we have been lucky that more lives were not lost and that we have been able to contain cases of avian influenza. But it may be only a matter of time before our luck runs out.

In the United States in 2017, over 9 billion chickens were killed for food. Before their deaths, the vast majority of these animals were packed into unsanitary factory farms, where disease can spread quickly and viruses can mix to create novel viruses that jump to humans. We all understand how social distancing works to slow the spread of COVID-19 in humans. But consider a barn full of 30,000 chickens, where each bird has only about one square foot of floor space. Infections can spread like wildfire.

The United States alone has 25,000 chicken farms, managed by farmers who come in contact with chickens every day. If each farmer employs two farmhands and has three family members who live on the farm, then there are 150,000 people who come in contact with countless chickens every year. This number doesn’t include the catching crews, the drivers who transport the animals to slaughter, or the slaughterhouse workers who handle the animals. There are millions of points of contact per year between chickens and humans, and each one is an opportunity for transmission of potentially deadly pathogens.

To be clear, we should not blame these farmers. Faced with few other viable career paths in declining rural areas, most chicken farmers and many pig farmers become bound by what some have termed “indentured servitude” by entering into restrictive contracts with large meat companies like Tyson and Pilgrim’s Pride. Farmers are forced to take on colossal debt simply to do business. Between 2012 and 2018, the Small Business Administration backed more than 1,500 loans averaging over $1 million each to poultry farmers. Nine in 10 farmers polled said that financial issues, business problems, or fear of losing their farms impacted their mental health.

But it’s not just farmers who are harmed by this system. Factory farming puts us all in danger. Our desire for cheap animal protein is driving climate change, antibiotic resistance, and pandemic risk. We must end factory farming and transition to an animal-free food system.

Mercy For Animals is working to build a kinder, more sustainable, and healthier food system. Every day, we work to move companies to adopt meaningful animal welfare standards for chickens. Our teams help companies and institutions add more plant-based options to their menus, thus reducing our reliance on animal agriculture. And now we are working with farmers through our Transfarmation Project to transition animal farms into plant-focused farms that can provide our communities with healthier food.


We know that raising and killing animals for food is not only inhumane but dangerous. It puts us and future generations at greater risk of the effects of climate change, antibiotic resistance, zoonotic viruses, and other threats.

Join us, and let’s build a compassionate food system together.
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